Order picking is the process of retrieving items from storage according to customer orders. It is significant to warehouse management because it typically accounts for over half of the operation costs.

In this research, an order picking system that is designed by applying lean principles is discussed. The discussion is focused on three important decisions: layout design, storage location assignment, and workload scheduling. Combination of existing strategies has been applied to layout design in order to achieve the goal of lean. Buffer trays are applied in the fast pick area to reduce the impact of imbalance between zones. Heuristics are developed to assign storage locations and schedule workload, to optimize the performance of the system.

The testing results show that the proposed warehouse with assignment and scheduling results obtained from the heuristics is more efficient than a traditional warehouse in terms of requested labor time of completing orders in one wave.